The present invention relates to a method of heating up a first gas-flow with a second gas-flow, particularly for heating gas for use in high-temperature processes such as the production of metal, garbage, incineration, etc., and to an apparatus for performing the method.
It is known per se to heat blast gas for use in blast furnaces by means of a gas heated in a plasma generator. See Swedish Pat. No. 73 04 333-3. The problem with this previously known process is the high temperature in combination with high gas velocity to which the lining is subjected. This results in excessive wear particularly where the extremely hot gas-flow is expelled.
Another problem is the uncontrolled and poor mixing of the gases, resulting in hot jets in the gas mass. This is particularly disadvantageous when solid and/or liquid fuel is to be mixed with the gas before it enters the blast furnace.
The object of the present invention is thus to eliminate the above drawbacks and effect a method of heating one gas with another gas in such a way that the defining walls are protected and that the gases are gradually and thoroughly mixed.